Vacuum switching system

ABSTRACT

A vacuum switching system having an evacuated housing and a plurality of electrical contacts therein. A buss is provided for internal connection to one of said contacts of said plurality of pairs. Another of said contacts may be connected to an external circuit. The other contacts of said pair are electrically connected to a shorting member and means are provided for electrically connecting and separating the pair of electrical contacts. Further, the system may comprise a plurality of sets of pairs of contacts with shielding means between adjacent sets. In addition, shielding means may be provided in the system wherever needed, in order to prevent splattering of parts of the system.

United States Patent 91 Miles VACUUM SWITCHING SYSTEM [75] Inventor:Floyd D. Miles, Saratoga, Calif.

[73] Assignee: International Telephone and Telegraph Corporation, NewYork, NY.

[22-] Filed: Jan. 3, 1972 [21] Appl. No.: 215,059

[52] US. Cl. ..200/144 B [51] Int. Cl. ..l-l0lh 33/66 [58] Field ofSearch ..200/144 B [56] References Cited UNITED STATES PATENTS 3,200,2228/1965 Hawkins ..200/144 B [1 11 3,73Lll26 51 May 1, 1973 PrimaryExaminerRobert S. Macon Attorney-C. Cornell Remsen, Jr. et al.

[57] ABSTRACT A vacuum switching system having an evacuated housing anda plurality of electrical contacts therein. A buss is provided forinternal connection to one of said contacts of said plurality of pairs.Another of said contacts may be connected to an external circuit. Theother contacts of said pair are electrically connected to a shortingmember and means are provided for electrically connecting and separatingthe pair of electrical contacts. Further, the system may comprise aplurality of sets of pairs of contacts with shielding means betweenadjacent sets. In addition, shielding means' may be provided in thesystem wherever needed, in order to prevent splattering of parts of thesystem.

4 Claims, 3 Drawing Figures VACUUM SWITCHING SYSTEM The inventionrelates in general to vacuum switching systems and, more particularly,to a multi-pole vacuum interrupter system.

BACKGROUND OF THE INVENTION With the advent of greater use ofunderground power systems, it has been found that prior art undergroundinstallations have been extremely large as well as expensive. In thecase of underground switching systems, two types of systems havepreviously been used. Where an air break system is"used,it has beenfound that a costly maintainance program must be provided in order tocontinuously replace worn out parts in the system. Alternatively, oilfilled switching members have been used, which have been found to behazardous in that explosions, as well as fires have occured. Moreover,these systems-are extremely large and are required to have extremelylarge vault installations.

In order to overcome the attendant disadvantages of prior artunderground switching systems, the present 4 invention is much smallerin physical size thereby required smaller vaults. Moreover, the safetyhazards to maintainance and installation men are eliminated. With theimproved safety and reduction in maintainace and physical sizes,installation problems which previously required a large crew areeliminated with the result that the entire switching system can beinstalled by a single person. Moreover, the unique modular constructionof the system allows a multiplicity of switching arrangements.

The advantages of the invention, both as to its construction and mode ofoperation, will be readily appreciated as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawings in which likereferenced numerals designate 7 like parts throughout thefigures.

BRIEF DESCRIPTION .OF THE DRAWINGS FIG. 1 depicts a front view partly insection of the switching system in accordance with the invention;

FIG. 2 illustrates a side view of the switching system of FIG. 1 takenalong the line 2-2 of-FIG. l; and

FIG. 3 shows a schematic diagram of the switching system to illustratethe alternative switching arrangements possible therewith.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawingsthere is shown in FIGS. 1 and 2, a unique vacuum switching system madein accordance with the principles of the invention. The system comprisesan elongated steel vacuum housing member 12 in which the contacts of theswitching system are mounted. The housing member 12 comprises a top wall14, side wallsl6, l8, and. a bottom wall 22, as well as end walls 24.Openings 26 are formed in the top wall through which conductor rods suchas the member 28 protrude therethrou gh. The opening 26 has a diametergreater than the conductor rod 28. The conductor rod 28 extends upwardlyfrom the housing member and terminates at a threaded portion 32 to whichan electrical conductor (not shown) may be secured.

A metallic ring 34 having a diameter approximately equal to the opening26 extends upwardly at one end from the opening and surrounds theconductor rod 28 but is spaced therefrom. The other end of the metallicring 34 has secured thereto a ceramic insulator shell 36 which alsosurrounds the conductor rod 28 and is spaced therefrom. Secured to theother end of the insulator shell 36 is one end of a metallic end hellwith the other end of the end bell being secured directly to theconductor rod 28 thus forming a vacuum seal between the conductor rod 28and the housing 12.

Formed in the bottom wall 22 of the housing are openings 38 into which ametallic diaphragm 42 is inserted. The diaphragm 42 provides a tightvacuum seal to the opening 38 of the housing. An opening 44 is centrallyformed in the diaphragm 42 and an actuating member is secured thereto.The connection between the diaphragm 42 and the housing opening 38 aswell as the actuating member 46 is such that a tight vacuum will remainin the housing after the connections have been made.

The actuating member 46 contains a downwardly facing shoulder 48 towhich a diaphragm shield 52 is secured. Further, the top surface 54 ofthe actuating member has secured thereto an insulator 56 at the bottomsurface thereof. The top surface of the insulator contains a connectingmember 58. A downwardly facing shield 60 is secured to the connectingmember 58. The connecting member 58 contains a reduced diameter section62 which fits into an opening formed in a generally rectangular shapedshorting bar 64. The top surface of the shorting bar 64 has securedthereto a pair of contacts 66, 68.

Secured to the bottom of the conductor rod 28 is a contact 72. Thecontact 72 is identical to the contact 66 and in the position shown inFIGS. 1 and 2 is electrically connected thereto. Further, a shield 73 issecured to the conductor rod 28 between the contact 72 and the opening26 in the top wall so as to protect the ceramic insulator shell 36 fromsplatter. A contact 74 is adjacent to the contact 68 and also in thepositions shown in FIGS. 1 and 2 is electrically connected thereto.

- The top surface of the contact 74 is secured to an internal bussingmember 76. Further, a header 78 is secured to the bussing memberdirectly above the contact 74 and thus forms a shield as well. Thecentral portion of the header is secured to a ceramic insulator whichelectrically isolates the internal bussing member 76 from the housing12. The header 78 is used to protect the insulator 80 from splatter. Theinsulator 80, in turn, is connected through a header 81 to the innersurface of top wall 14.

, The internal bussing member 76 extends lengthwise along the housingand is secured to a conductive shield 82. The conductive shield forms apartition between adjacent sets of contacts in the housing member, andis electrically isolated from the housing 12. Thus, an identicalarrangement as that shown in FIG. 2 is separated from the arrangement ofFIG. 2 by means of the conductive shield 82. As can be readily seen,downward movement of the actuating member 46 in turn causes the shortingbar 64 and the contacts 66, 68 secured thereto to be separated from thecontacts 72 and 74, respectively. This, in turn, would electricallyReferring now to FIG. 3, there is shown a schematic embodiment for atypical arrangement utilizing a plu rality of sets of contacts of thetype shown in FIG. 2. In FIG. 3, bussing bars 64a, 64b and 640, are usedto interconnect the contacts 72a and 74a, 72b and 74b, and

72c and 740, respectively. The contacts 74a, 74b, 740, in turn, areconnected to an internal bussing arrangement formed by theinterconnected members 76a, 76b, and 76c. Thus, as can be readily seen,movement of any one or all of thecontacts 64, 64b, and 64c can cause avariety of interconnections between the various terminals of thecircuit.

Further, since the device is intended for use with very large currents,it is necessary to provide shields 52, 60, 73, 78 and 82 to preventspattering which may occur. Moreover, as is conventional, the entirehousing is surrounded by a conventional filled epoxy potting compound98.

What is claimed is:

1. A vacuum switching system comprising:

an evacuated housing;

a plurality of sets of electrical contacts each comprising at least twopairs of contacts, each of said pairs comprising first and secondcontacts;

bussing means for internally connecting all of said first contacts ofone of said pairs of each of said sets together;

and shorting means electrically and mechanically joining said secondcontacts of each of said pairs in each of said sets.

2. Apparatus according to claim 1 including a plurality of discreteexternal electrical terminal providing external connections, one fromeach first contact of the other pair of said contacts in each of saidsets.

3. Apparatus according to claim I in which said first contacts of saidpairs of contacts in each of said sets are fixed contacts and saidsecond contacts joined by said shorting means are the moving contacts,thereby forming a double vacuum-gap switch within each of said sets.

4. Apparatus according to claim 1 in which said bussing means aresecured to said housing through an insulating member and shielding meansare provided for prevention of spatter deposition from said contactsonto said insulating member.

1. A vacuum switching system comprising: an evacuated housing; aplurality of sets of electrical contacts each comprising at least twopairs of contacts, each of said pairs comprising first and secondcontacts; bussing means for internally connecting all of said firstcontacts of one of said pairs of each of said sets together; andshorting means electrically and mechanically joining said secondcontacts of each of said pairs in each of said sets.
 2. Apparatusaccording to claim 1 including a plurality of discrete externalelectrical terminal providing external connections, one from each firstcontact of the other pair of said contacts in each of said sets. 3.Apparatus according to claim 1 in which said first contacts of saidpairs of contacts in each of said sets are fixed contacts and saidsecond contacts joined by said shorting means are the moving contacts,thereby forming a double vacuum-gap switch within each of said sets. 4.Apparatus according to claim 1 in which said bussing means are securedto said housing through an insulating member and shielding means areprovided for prevention of spatter deposition from said contacts ontosaid insulating member.